Prime Minister Thaksin Shinawatra says some leaders of a separatist insurgency in southern Thailand have fled to neighboring Malaysia. The remark came after police arrested four alleged leaders of the insurgency and said they will stand trial for treason.

The Thai prime minister says two key figures in the insurgency in the south have fled to Malaysia as security forces continue to hunt what he called 100 core members. Thaksin Shinawatra says some rebel leaders received training in Malaysia, although he adds that he does not believe the Malaysian government knew about it.

Mr. Thaksin made the remarks Friday as authorities brought to Bangkok four suspected rebel leaders who were arrested earlier this week. The four men, teachers at an Islamic school in the southernmost province of Narathiwat, have been charged with treason and could face the death penalty.

Mr. Thaksin told reporters that he believes the situation in the south is improving, although there may be setbacks.

"Better and better. It might be temporary fighting back, a little bit. But I think we are in good control," he said.

However, the head of the Thai Law Society, human rights activist Somchai Homlaor, does not agree.

"I don't think so," he said. "Insofar as there is no trust between the government and the people, and the police and authorities still use their power in really excessive or abusive ways, I think these arrests will not help."

Mr. Somchai says months of repression by security forces have united local Muslims against the central government of mostly Buddhist Thailand. And he says the harsh effort to halt the insurgency has made Muslims more sympathetic toward militants seeking to create a separate state in the predominantly Muslim south.

The Thai leader told reporters that one of the latest detainees is believed to have organized a raid last January on a military base in which four soldiers were killed and hundreds of weapons were seized. That raid sparked a year of violence in which some 500 people have been killed.

There are fears that the coming anniversary of that raid could be marked with new attacks in the south, or elsewhere in Thailand.

On Friday, an independent commission was handing a report to the prime minister about the deaths of more than 80 Muslims when security forces crushed a protest over the government's tactics in the south. The report is to be released to the public next week.